A few months after teen shooters killed 12 classmates and her father at Columbine High School, Coni Sanders was standing in line at a grocery store with her young daughter when they came face to face with the magazine cover.

It showed the two gunmen who had carried out one of the deadliest school shootings in U.S. history. Sanders realized that few people knew much about her father, who saved countless lives. But virtually everyone knew the names and the tiniest of details about the attackers who carried out the carnage.

In the decades since Columbine, a growing movement has urged news organizations to refrain from naming the shooters in mass slayings and to cease the steady drumbeat of biographical information about them. Critics say giving the assailants notoriety offers little to help understand the attacks and instead fuels celebrity-style coverage that only encourages future attacks.

The 1999 Colorado attack continues to motivate mass shooters, including the two men who this week stormed their former school in Brazil, killing seven people.

The gunman who attacked two mosques in New Zealand on Friday, killing at least 49 people, was said to have been inspired by the man who in 2015 killed nine black worshippers at a church in Charleston, South Carolina.

Adam Lankford, a criminologist at the University of Alabama, who has studied the influence of media coverage on future shooters, said it’s vitally important to avoid excessive coverage of gunmen.

“A lot of these shooters want to be treated like celebrities. They want to be famous. So the key is to not give them that treatment,” he said.

The notion hit close to home for Sanders. Seemingly everywhere she turned — the grocery store, a restaurant, a newspaper or magazine — she would see the faces of the Columbine attackers and hear or read about them. Even in her own home, she was bombarded with their deeds on TV.

Everyone knew their names. “And if you said the two together, they automatically knew it was Columbine,” Sanders said. “The media was so fascinated — and so was our country and the world — that they really grasped onto this every detail. Time and time again, we couldn’t escape it.”

Criminologists who study mass shootings say the vast majority of shooters are seeking infamy and soak up the coverage as a guide.

Just four days after the 2017 Las Vegas concert shooting, which stands as the deadliest mass shooting in modern U.S. history, Lankford published a paper urging journalists to refrain from using shooters’ names or going into exhaustive detail about their crimes.

These attackers, he argued, are trying to outdo previous shooters with higher death tolls. Media coverage serves only to encourage copycats.

Late last year, the Trump administration’s federal Commission on School Safety called on the media to refrain from reporting the names and photos of mass shooters. It was one of the rare moments when gun-rights advocates and gun-control activists agreed.

“To suggest that the media alone is to blame or is primarily at fault for this epidemic of mass shootings would vastly oversimply this issue,” said Adam Skaggs, chief counsel for the Giffords Law Center, which works to curb gun violence.

Skaggs said he is “somewhat sympathetic to journalists’ impulse to cover clearly important and newsworthy events and to get at the truth. ... But there’s a balance that can be struck between ensuring the public has enough information ... and not giving undue attention to perpetrators of heinous acts.”

Studies show a contagion effect from coverage of both homicides and suicides.

The Columbine shooters, in particular, have an almost cult-like status, with some followers seeking to emulate their trench-coat attire and expressing admiration for their crime, which some have attributed to bullying. The gunman in the 2012 Sandy Hook Elementary School shooting kept a detailed journal of decades’ worth of mass shootings.

James Alan Fox, a professor at Northeastern University who has studied mass shootings, said naming shooters is not the problem. Instead, he blamed over-the-top coverage that includes irrelevant details about the killers, such as their writings and their backgrounds, that “unnecessarily humanizes them.”

“We sometimes come to know more about them — their interests and their disappointments — than we do about our next-door neighbors,” Fox said.

Law enforcement agencies have taken a lead, most recently with the Aurora, Illinois, police chief, who uttered just once the name of the gunman who killed five co-workers and wounded five officers last month.

“I said his name one time for the media, and I will never let it cross my lips again,” Chief Kristen Ziman said in a Facebook post.

Some media, most notably CNN’s Anderson Cooper, have made a point of avoiding using the name of these gunmen.

The Associated Press names suspects identified by law enforcement in major crimes. However, in cases in which the crime is carried out seeking publicity, the AP strives to restrict the mention of the name to the minimum needed to inform the public, while avoiding descriptions that might serve a criminal’s desire for publicity or self-glorification, said John Daniszewski, the AP’s vice president and editor-at-large for standards.

For Caren and Tom Teves, the cause is personal. Their son Alex was among those killed in an Aurora, Colorado, movie theater in 2012.

They were both traveling out of state when the shooting happened, and it took 15 hours for them to learn the fate of their son. During those hours, they heard repeatedly about the shooter but virtually nothing about the victims.

Not long after, they created the No Notoriety movement, encouraging media to stick to reporting relevant facts rather than the smallest of biographical details. They also recommend publishing images of the shooter in places that are not prominent, steering clear of “hero” poses or images showing them holding weapons, and not publishing any manifestos.

“We never say don’t use the name. What we say is use the name responsibly and don’t turn them into anti-heroes,” Tom Teves said. “Let’s portray them for what they are: They’re horrible human beings that are completely skewed in their perception of reality, and their one claim to fortune is sneaking up behind you and shooting you.”